I want to take a train from Paris to Berlin at night. I'm trying to book via bahn.de, but I've also looked at thetrainline.com.
For next Wednesday, bahn.de offers me an option with connections in Frankfurt and Leipzig. So that's Paris → Frankfurt (TGV), Frankfurt → Leipzig (NJ), Leipzig → Berlin (ICE).
The Nightjet continues to Berlin. I would rather stay in and continue sleeping, rather than change to the Leipzig → Berlin train (even though that shaves an hour of the travel, as NJ is really slow on that section), especially as this change is really early.
I cannot play with the connection times, because the connection in Frankfurt is longer than in Leipzig.
I cannot filter by train type, because TGV and ICE fall under the same box.
I can book Frankfurt → Berlin (either via the NJ website, or via bahn.de, by looking at just that part of the trip), but that would be two separate tickets. I'd rather avoid that.
Is there an option that I've missed to explain to DB that I don't mind a longer trip and would like to be staying in that train?
As pointed out by Gilles' answer, this is not systematically the case. Both next Monday and Tuesday offer both the faster and the slower route. But for some days, like next Wednesday and next Saturday, only the fast route with a change in Leipzig is offered.